import java.util.Random;


public class randomip {

	public static  long ipToLong(String strIp){
        long[] ip = new long[4];
        //先找到IP地址字符串中.的位置
        int position1 = strIp.indexOf(".");
        int position2 = strIp.indexOf(".", position1 + 1);
        int position3 = strIp.indexOf(".", position2 + 1);
        //将每个.之间的字符串转换成整型
        ip[0] = Long.parseLong(strIp.substring(0, position1));
        ip[1] = Long.parseLong(strIp.substring(position1+1, position2));
        ip[2] = Long.parseLong(strIp.substring(position2+1, position3));
        ip[3] = Long.parseLong(strIp.substring(position3+1));
        return (ip[0] << 24) + (ip[1] << 16) + (ip[2] <<  8 ) + ip[3];
    }
	
	
	
	public static String longToIP(long longIp) {
        StringBuffer sb = new StringBuffer("");
        //直接右移24位
        sb.append(String.valueOf((longIp >>> 24)));
        sb.append(".");
        //将高8位置0，然后右移16位
        sb.append(String.valueOf((longIp & 0x00FFFFFF) >>> 16));
        sb.append(".");
        //将高16位置0，然后右移8位
        sb.append(String.valueOf((longIp & 0x0000FFFF) >>>  8 ));
        sb.append(".");
        //将高24位置0
        sb.append(String.valueOf((longIp & 0x000000FF)));
        return sb.toString();
    }
	
	public static int getRanNum(int min,int max){
		Random r1 = new Random();
		return r1.nextInt(max-min+1)+min;
	}
	
	
	public static void main(String[] args) {
		String beginip = "24.142.128.0";
		String endip = "24.143.47.255";
		long bip = ipToLong(beginip);
		long eip = ipToLong(endip);
		//System.out.println(getRanNum((int)bip, (int)eip));
		System.out.println(longToIP((long)getRanNum((int)bip, (int)eip)));
		
	}

}
